Is it possible to weld rack mounts to a to frame?

Is it a good idea?

I commute on an on one scandal. 4 miles on the road each way, that occasionally gets extended to 10 or 20 miles of paths and mild trails.

It has a rack held on with p clips as the frame has no mounts for a rack or mudguard. 

Is it possible to get rack mounts welded on? I broke a p clip and had the rack bouncing into the cassette last week.

The cheap solution is clearly just carry spare p clips for the 3 times I've broken one in the last  3 years/ 3000 miles. However I'd like to put my 15kg 2 year old on her child seat on the back of this bike. P clips aren't going to cut it.

Thanks!